Stock feed



L. K. BRAREN July 19, 1927.

STOCK FEED Original Filed Nov. 28. 1922 2 Sheets-Sheet 2 m r x J m. fw do M 5 V g M HJ lb fl M. 6 L, .m F Hf 5. 5 w a GM L. 5 9.W/. i m R w /9 .m 2 9 0 2 w v. w "M n 45 67.

Patented July 19, 1927.

UNITED STATES PATENT OFFICE.

. LORENZ KONBAD BRAREN, OF MUNICH, GERMANY, ASSIGNOB TO FIRM FRIED- RICH. :oEcxnL, r'annrx mm rnlizisronsmnonamx UND MASGHINENBAU, or

MUNICH, GERMANY.

STOCK FEED.

Original application .nled November 28, 1922, Serial No. 603,871, and in Germany December 18, 1921.

Divided and this application filed June 4, 1924. Serial Ila- 717,7145

The present invention relates to stock feeds formoving automatically a bar of material through a machine and may for instance be employed to advantage in connection with screwmaking and turning lathes. Such an application is shown and described in my copending application, filed Nov. 28, 1922, Serial No. 603,871. The object of the invention is to provide a mechanism which advances the material only through axial movements without usingseparate instrumentalities for opening and closing the jaws. This stock feed is designed to permit a very accurate control of the material and is very simple in. construction.

Another object of the invention is to provide an improved mechanism for stopping the machine as soon as the bar of material has been used up.

In order that this my invention may be more readily understood reference is made to the accompanying sheets of drawings which show now this invention may be carried into practical effect.

Fig. 1 is a front elevation of an automatic screwmachine with my invention applied thereto, partly in section.

Fig. 2 is a top view to Figure 1.

Fig.3 is a sectional view of the feeding device proper on anenlarged scale.

Fig. 4 is a section through a spring collet according to the line A-A in Fig. 3.

Fig. 5 shows the actuating slide for the feeding device. I

Fig. 6 is a perspective view of the drive clutch engaging lever.

Referring to the drawings in which like characters of reference indicate corresponding parts wherever occurring, the driving pulley 1 receives its motion through a belt directly from a ulley on a motor or on a suitable counters aft which drive has not been shown 'being immaterial to the present invention.

The driving pulley 1 is formed on the inside to mate with a cone clutch 2 which is fastened rigidly to a drive shaft -3. The hub .of pulley 1 is bored to turn and slide freely on the outside of a bushing 4 which latteris pressed into a hub of a cover 5 of a gearbox 6. A spring 7 tends to hold the coupling out of engagement, a thrust plate 8 being interposedbetween the spring 7 and the cone clutch 2.

A handle 9 for starting the machine is pivoted on a pm 10 which is fastened in a In 11 of the gear case cover 5. A lever 12 also pivoting on pin 10, is forked to reach out over a hub of the pulley 1 and carries two sliding shoes 13 fitting in a groove 14 provided in the hub. On the opposite side the lever 12 extends with plate like portions 15 over and under the handle 9, a part 16 con- 6). A pin 17 fastened in the handle 9 passes through a slot in the top plate of the lever 12 and. limits the movement of the handle 9 and the lever 12 in relation to each other, a spring 18 tending to force them apart. A nose 19 on the end of a lever 20, which is pivoted to a lug of the gear case 6, can hook under a plate 21 fastened to the handle 9. A spring 22 pulls the lever 20 up against the plate 21.

In order to engage the driving pulley 1 with the cone clutch 2 the handle 9 is pushed towards the left until the nose 19 on the lever 20 can snap upwards under the action of the spring 22 and hook in back of the end of the plate 21 preventing thus the return of the handle 9. The lever 12 moves together with handle 9 until pulley 1 has been brought into contact with the clutch member 2'. A further movement of the handle 9 compresses the spring 18 providing thus for the necessary coupling pressure. In order to keep the coelficient' of friction in the cone clutch constant a lubricant retainer 23 has been fas tened to pulley 1. To stop the machine it is only necessary to'push nose 19 downward because the spring 7 tends to return pulley 1, lever 12 and handle 9 to nonrunning-position.

The drive'shaft 3 transmits the movement from the clutch member through two pair of gears 24, 25 and 26, 27'to ain shaft 28 which is 'ournaled in beari. s of the gear case and t e gear case cover. 'This shaft exnecting these two plates together (see'Fig.

tends over into the main fran'ie :29 of the machine and rotates there agear lil. Through gearing 31, 32 and 33, 34.- mow-ment is being transmitted from the main .baft 28 to a cam shaft 35 on whicha double cam 36, 37 has'been mounted. These can reciprocate a "main spind e 55, while a bushing 66 serves the same purpose for the retainer 63 intoslide 38, two rollers 39 and LO-being interposed. On the slide is provided an adjustable guide 41 of channel section. A roller 42 carried by an arm 43 slides in the channel of the uide 41 and is moved crossways by the reciprocating slide, the amount of movement depending on the angular adjustmentof the guide. The arm'43 is mounted on a bushin 44 which is journaled coaxially with the main shaft 28 free to slide back and forth. The mechanisms described above are more fully shown and described in my copending application, filed Nov. 28, 1922, Serial No. 603,871. A gooseneck portion of the arm 43 extends around a bushing 45 and fits with two keylike projections into a groove 46 of said bushing transmitting thus the reciprocating movement to the bushing. The latter slides in a bushing 47 pressed into a hub of the gear case 6. The bushing 45 is prevented from turning by a key 48. A tubular part 49 fits rotatably into the bore of the bushing 45, and is located axially by two nuts 52 and a washer 53. Felt inserts in longitudinal holes insure a good lubrication. The-re is another tubular member 54 screwed over the enlarged end of the part 49 and slidingly located in a bore of the main spindle 55, a' key preventing rotation. Part 49 serves as a retainer for three steel balls 56 which fit easily between the faces of the parts 49 and 54 and rest in grooves cut with an incline onto the back of the three jaws of a spring collet 57 which is slidin ly located in a bore of the part 54 and whic is pressed towards the right by a spring 58 making thus the balls roll up on the inclined grooves, close the jaws of the collet, and gri the rod of material 59. The parts just escribed are the complete feeding mechanism.

' Working together with the'feeding mechanism there is provided a material holding spring collet 60, with three balls 61 'work- 'aws, a-spring 62 for closing the jaws and a all retainer 63. Part 63 is screwed onto the noseof the main spindle 55. A cap 64 serves for holding the balls in place. A nut 65 screwed to the end of the spring collet 64 helps to uide the collet in the bore of the which it is pressed.

The bar of material 59 is guided loosely on its entrance into the machine in a bushing 67. Guide bushings 68 and 69 which are pressed into the ends of the spring collets 57 and 60 serve especially for steadying material of small diameter. All bushings and collets through which the rod of material is assing are countersunk on the entering si e.

The two spring collets are arranged in such a manner that the material may pass through ing in similar inclined grooves of the collet them readily in the feeding direction be-- cause end pressure applied in this direction is transmitted by frlction to the collet, releasing the balls and allowing the material to slide through easily. Any end pressure in the opposite direction however forces the balls tighter onto the jaws, increasing the grip on the material in ratio with the end pressure applied, with suitable inclination of the grooves locking the rod entirely.

The whole feeding process therefore requires only a movement back and forth of the spring collet 5,7, which is transmitted through the feed actuating arm 43 as previously described; The material is always held securely by one of the collets thus insuring an exactand uniform feed.

To prevent any end movement of the main spindle 55, there have beenprovided two bearings 70 and 71 with a tapering bore of which the former is pressed into, while the second is held adjust-ably by screws inhubs of the main frame 29. On the central portion of the main spindle teeth 72 have been cut in engagement with the gear 30, which is driven by the main shaft 28 and-supported by two bearings 73 and 74 with similar tapering bores as the bearings 70 and 71 have. To

revent the lubricant, which is thrown in arge volume onto the material and the cutting t ools, from being thrown oifby the fast rotating spindle an oil guard 75 is pushed into a corresponding recess in the bearin 7 O, a T slot being cut into the oilguard to e fect a slightly springing action.

Having now fully explained my invention I do not wish to be understood as limiting myself to the exact details of construction as obviously man modifications will occur to a person skilie in the art.

What I claim is:

1. In turmng andscrew cutting machines, a stock feed comprising a stationary automatic gripping device operated by the movement of the stock in one direction to grip and hold the same, and upon movement in the opposite direction to release the same, a mova 1e automatic feeding mechanism including jaws frictionall engaging the stock and operated thereby uring movement in one direction to grip and advance the stock, and adapted u 'on movement in the opposite direction to sllde along the same and also including a reciprocally mounted non-rotatable tubular part enclrcling the jaws and serving to force the latter into frictional enonto the material.

inclined grooves on the back of the jaws of said sprin collet, a ball retainer and 11 spring, sai spring making the balls roll up in the inclined grooves and clamp the jaws 3. In a stock feed a gripping mechanism comprising a spring collet, having a plurality of jaws and an inclined groove on the back of' each jaw, steel balls arranged to operate in said inclined grooves and means for causing said balls to roll up in said inclirlied grooves and clamp the rod of materia 4. In a stock feed a gripping mechanism comprising a member for ripping the bar of stock, a plurality of rofiing elements in contact with said ripping member a container for said rol in elements an means for causing .said rolling elements to force said gripping member onto the bar of stock,

5. In a stock feed a gripping mechanism comprising a member for gripping the bar of stock, inclined'surfaces on said gripping member, rolling elements operating on said inclined surfaces and a container for said rolling elements. a

6. In a stock feed a gripping mechanism comprising a member for gripping the bar of material, inclined surfaces on said gripping member, an external race, rolling elements operatin and said gripping member on said inclined surfaces and means for causing saidrolling elements to run up on said inclined sur;

faces. a

7. In a stock feed a'gripping mechanism comprising a spring collet provided with movable jaws, inclined surfaces on the back of the jaws of said spring collet, a race, rolling elements operating between said race and said race and jaws having relativel between said external race.

tween said rolling elements and said spring collet'and different means for limiting the movement of said rolling elements.

8. In a stock feed, a gripping mechanism comprising a collet provided with spring jaws, a race about saidcollet, rolling elements between said-race and collet jaws,

clined surfaces operating upon re ativemovement therebetween to close said jaws to grip the stock, spring actuated means tending to effect a relative movement of said parts to close said jaws, and means for causing a relative movement between said stock and awe to operate the latter by-the frictiona movement in one direction.

9. In a stock feed, a pair ofgripping 'mechanisms each comprising a collet having spring jaws, a race a out said 'jaws having a surface inclined relatively to the surface of said jaws, rolling elements between said surfaces a spring operating between saidengagement therebetween, during race an jaws tending to move said arts to close said jaws, said gripping mec anisms' having frictional en agement with-the stock,

and being arrange for operation by such frictional enga ement to cause said jaws to grip the stock during movement in opposite directions respectively, and means for reciprocating one of said gripping mechanisms for idle movement along the stock while the latter is held by the other of said mechanisms and for gripping and advancing the stock during movement in the opposite direction. v 1

' In testimon whereof I afiix my si nature. LoRimz KONRAD BRAIiEN. 

